• Title/Summary/Keyword: 2차경화

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Properties of Non-Sintered Cement Pastes Immersed in Sea Waters at Different Temperatures for Binders Mixed with Different Ratios (침지된 해수 온도 및 결합재 혼합비에 따른 비소성 시멘트의 강도 특성)

  • Jun, Yubin;Kim, Tae-Wan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.5
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    • pp.75-84
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    • 2016
  • This paper presents an investigation of the mechanical properties on non-sintered cement pastes immersed in sea waters at three different temperatures. The non-sintered cement pastes were synthesized using blended binder(Class F fly ash; FA and ground granulated blast furnace slag; GGBFS) and alkali activator(sodium hydroxide and sodium silicate). Binders were prepared by mixing the FA and GGBFS in different blend weight ratios of 6:4, 7:3 and 8:2. The alkali activators were used 5wt% of blended binder, respectively. Calcium carbonate was used as an chemical additive. The compressive strength, bulk density and absorption of alkali-activated FA-GGBFS blends pastes were measured at 3 and 28 days after immersed in sea waters at three different temperatures($5^{\circ}C$, $15^{\circ}C$ and $25^{\circ}C$). The XRD and SEM tests of the pastes were conducted at 28 days. Water-soluble chloride(free chloride) and acid-soluble chloride(total chloride) contents in the pastes were also measured after 28 days immersion in sea water. The experimental results showed that increasing the content of FA in alkali-activated FA-GGBFS blends pastes immersed in sea water increases the absorption, water-soluble chloride content and acid-soluble chloride content, and reduces the compressive strength and bulk density. And it was found that there was a variation of strength change for the alkali-activated FA-GGBFS blends pastes immersed in sea waters at three different temperatures that depends on the blending ratio of FA and GGBFS.

Curing Behavior and Interfacial Properties of Electrodeposited Carbon Fiber/Epoxy Composites by Electrical Resistivity Measurement under Tensile/Compressive Tests (전기증착된 탄소섬유/에폭시 복합재료의 인장/압축 하중하에서의 전기저항 측정법을 이용한 경화 및 계면특성)

  • Park, Joung-Man;Lee, Sang-Il;Kim, Jin-Won
    • Journal of Adhesion and Interface
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    • v.2 no.1
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    • pp.9-17
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    • 2001
  • Curing behavior and interfacial properties were evaluated using electrical resistance measurement and tensile/compressive fragmentation test. Electrical resistivity difference (${\Delta}R$) during curing process was not observed in a bare carbon fiber. On the other hand, ${\Delta}R$ appeared due to the matrix contraction in single-carbon fiber/epoxy composite. Logarithmic electrical resistivity of the untreated single-carbon fiber composite increased suddenly to the infinity when the fiber fracture occurred under tensile loading, whereas that of the ED composite reached relatively broadly up to the infinity. Comparing to the untreated case, interfacial shear strength (IFSS) of the ED treated composite increased significantly in both tensile fragmentation and compressive Broutman test. Microfailure modes of the untreated and the ED treated fiber composite showed the debonding and the cone shapes in tensile test, respectively. For compressive test, fractures of diagonal slippage were observed in both untreated and the ED treated composite. Sharp-end shape fractures exhibited in the untreated composite, whereas relatively dull fractures showed in the ED Heated composite. It is proved that ED treatments affected differently on the interfacial adhesion and microfailure mechanism under tensile/compressive tests.

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Effect of Chlorogenic Acid on the Concentrations of Serum and Hepatic Lipid in Rats (클로로겐산이 콜레스테롤 투여 흰쥐의 지질 농도에 미치는 영향)

  • Cha, Jae-Young;Kim, Dae-Jin;Cho, Young-Su
    • Applied Biological Chemistry
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    • v.43 no.2
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    • pp.153-157
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    • 2000
  • Effect of chlorogenic acid, one of polyphenolic compounds, on the concentrations of lipid in serum and hepatic lipid, serum glucose, and urinary protein in Sprague Dawley rats for 14 days was investigated. The concentration of serum total cholesterol was increased in the cholesterol group compared with the control group, while it was decreased in the cholesterol+chlorogenic acid group. The concentrations of hepatic triacylglycerol and cholesterol were increased in the cholesterol group, while these were not altered by the supplementation of chlorogenic acid. The concentrations of serum glucose and urinary protein were higher in the cholesterol+chlorogenic acid group than the control and the cholesterol groups. These results suggest that chlorogenic acid exerts a hypocholesterolemic effect in the rats fed cholesterol.

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Effects of Mulberry Leaf Tea Fermented by Monascus pilosus on Body Weight and Hepatic Antioxidant Enzyme Activities in Mouse Fed High-Fat Diet (Monascus pilosus 발효 뽕잎차가 고지방 식이 마우스의 체중과 간 조직 항산화계 효소 활성에 미치는 영향)

  • Lee, Sang-Il;Lee, Ye-Kyung;Lee, In-Ae;Choi, Jongkeun;Kim, Soon-Dong;Suh, Joo-Won
    • The Korean Journal of Food And Nutrition
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    • v.26 no.1
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    • pp.66-77
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    • 2013
  • In this study, we investigated the preventive effects of the mulberry leaf tea fermented by Monascus pilosus on high fat-induced obesity, hyperlipidemia, and fatty liver in mice. Non-fermented mulberry leaf tea powder (UM) and fermented mulberry leaf tea powder (FM) were supplemented with high-fat diet at 2% (wt/wt) dosage for 8 weeks. Both UM and FM lowered body weight gain, feed efficiency ratio, epididymal fat, serum triglyceride, total cholesterol and LDL-cholesterol increased markedly with high fat diet (HC) in mice. FM showed more significant effects when it was compared with UM. In addition, Hepatic lipid peroxides and xanthin oxidase activities of the UM and FM were significantly lower than those of HC, despite the lack of a big difference in the amount of hepatic GSH. Activities of ROS scavenging enzymes and serum alanine aminotransferase activity were also examined as a parameter of hepatic damage. The UM and FM groups showed a recovery to NC group from significant changes induced by HC. Finally, histopathological analyses of liver samples revealed a decrease of lipid accumulation in hepatocytes in the UM and FM groups. These results suggest that UM and especially FM can reduce the development of obesity, hyperlipidemia and fatty liver.

Effect of Gastrodiae rhizoma Fractions on Serum Lipid Concentrations in Rats Fed with High Fat Diet (천마 분획물이 고지방식이를 급여한 흰쥐의 혈청 지질농도에 미치는 영향)

  • Hong, Hee-Do;Kim, Young-Chan;Keum, In-Kyung;Kim, Sung-Soo;Kim, Kyung-Im;Han, Chan-Kyu
    • Applied Biological Chemistry
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    • v.48 no.4
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    • pp.370-374
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    • 2005
  • This study was carried out to investigate the effect of Gastrodiae rhizoma fractions on serum lipid profiles and atherogenic index (AI) in male S.D. rats fed a high fat diet supplemented with 10 : 2 : 1% (w/w) of lard, corn oil, and cholesterol during the entire 12-week experimental period. Forty-eight rats were randomly divided into four groups; A (low molecule), B (polysaccharide), C (protein) fractions of Gastrodiae rhizoma, respectively, and D (high fat diet as control). Body weight gain, diet intake and feed efficiency ratio did not differ significantly among the groups during the experimental period, but final body weight was on the average 44 g higher in control compared with the three groups of Gastrodiae rhizoma $(A{\sim}C)$. TC and TG levels of group B when compared with control were each decreased by an average of 21.5% and 39.6%, respectively. HDL-cholesterol level was markedly higher in group C than group A and B of Gastrodiae rhizoma. LDL-cholesterol levels of Gastrodiae rhizoma groups $(A{\sim}C)$ were significantly lower than control. AI was significantly lower in group C at 1.45 than the other two Gastrodiae rhizoma at $1.94{\sim}2.05$ and control of 2.12. From the findings, it is feasible for water soluble and high molecular weight components of Gastrodiae rhizoma like polysacchride and protein fractions to be considered as functional components for improving hyperlipidemia.

송화가루를 첨가한 우리밀 식빵의 제빵 특성

  • 이혜숙;김문용;조영숙;전순실;박정로
    • Proceedings of the Korean Journal of Food and Nutrition Conference
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    • 2000.12a
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    • pp.50.2-50
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    • 2000
  • 우리나라 전역에 자생하는 소나무의 화분은 건강 식품의 하나로 당질, 단백질, 지질 중 PUFA와 식물성 sterol류, 무기질뿐만 아니라 자연의 항생물질, 효소, 호르몬, 성장물질 및 미지의 유효물질들을 다량 함유하고 있으며, 특히 강장작용, 심장병, 신경장애, 급만성전립선염, 동맥경화, 빈혈 및 간장해독 효과가 밝혀짐에 따라 송화가루에 대한 관심이 증대되고 있다 본 실험에서는 우리밀에 송화가루를 1%,2%,3% 첨가했을 때 제빵적성에 미치는 효과를 알아보기 위하여 반죽의 물성, 호화점도변화, 수분함량, 1차 발효손실률, 굽기 손실률, 색도, 부피 측정, 조직감, 노화도, 주사현미경 관찰, mold-free shelf-life 및 관능검사를 실시해서 최적 배합조건을 찾고자 하였다.

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A RADIOGRAPHIC ANALYSIS OF OSTEOSCLEROSIS OF THE JAWS (악골에 발생된 골경화증에 대한 방사선학적 연구)

  • Park Tae-Won
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.14 no.1
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    • pp.153-161
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    • 1984
  • Orthopantomograph는 치과진료에서 가장 일반적인 국외촬영방법으로 이용되고 있다. 저자는 1983년 서울대학교병원 치과진료부 치과방사선과에 래원한 환자중 Orthopantomogram을 촬영한 2,160명을 대상으로 골경화증의 성별, 연령별 발생빈도와 발생부위, 경화상의 크기, 모양등을 분류하고 특발성 골경화증과 condensing osteitis에 관하여 관찰하였든 바 다음과 같은 결과를 얻었다. 1. Idiopathic osteosclerosis의 발현율은 16.0%, condensing osteitis의 발현율은 9.8%였고 남녀간의 차이는 없었다. 2. 골경화증의 호발부위는 하악소구치, 대구치부위였고, 상악에서의 발생율은 적었다. 3. 골경화상의 크기는 idiopathic osteosclerosis는 10㎜이내였고, condensing osteitis는 10-20㎜의 폭경을 가지고 있었다. 4. 골경화상의 형태, 건강골과의 경계 및 발현되는 상태는 일정하지 않았다.

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A Study on Serum Lipid Levels in Elderly People in Wando Area - Based on Age, BMI, WHR - (완도지역 성인 및 노인의 혈청지질 수준에 관한 연구(I) - 연령, 신체 계측치를 중심으로 -)

  • Cha, Bok-Kyeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.1
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    • pp.68-77
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    • 2006
  • This study was peformed to document the association between nutrient intakes, body mass index (BMI), waist/hip ratio (WHR), and a major risk factor for chronic diseases. A three-day dietary intake survey, using a 24 hour recall method, was obtained from 187 subjects aged 46 to 84 (mean age 65.3) living in Wando island area. The average daily mean energy intakes were 1869.0 kcal for male and 1943.9 kcal for female, respectively. Daily intakes of protein for male and female were 28.0 and 30.4 g, and those of fat were 31.5 and 28.51 g, respectively Carbohydrate dependency was decreased with age. Protein dependency was increased with age. The mean intakes of energy, protein, Vit. A, Vit. D, Vit. E, Ca, Zn did not meet Korean RDA for elderly. The level of serum triglyceride was higher in males than in females and showed the tendency to increase with age in both sexes, whereas HDL-cholesterol tended to decrease with age in both sexes. The levels of serum total-cholesterol and LDL-cholesterol were significantly higher in males than in females, particularly in the age of $46\~59$ (p<0.05). The level of atherogenic index (AI) was significantly higher in females than in males, particularly in the age of 80 and over (p<0.05) Based on these results, it is evident that people in island area did not consume enough nutrient. Specially, dietary intake of protein was not adequate. This study implies that triglyceride, total-cholesterol, LDL-cholesterol, AI were increased with increasing age, BMI and WHR.

The Effect of Red-Yeast-Rice Supplement on Serum Lipid Profile and Glucose Control in Subjects with Impaired Fasting Glucose or Impaired Glucose Tolerance (공복 혈당장애 및 내당능장애자에서 홍국의 섭취가 혈중지질 및 혈당 조절에 미치는 영향)

  • Kang, Mi-Ran;Kim, Ji-Young;Hyun, Yae-Jung;Kim, Hyae-Jin;Yeo, Hyun-Yang;Song, Young-Duk;Lee, Jong-Ho
    • Journal of Nutrition and Health
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    • v.41 no.1
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    • pp.31-40
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    • 2008
  • This study was aimed at evaluating the effect of red-yeast-rice supplementation on cholesterol-lowering and glucose control in subjects with impaired fasting glucose (IFT) or impaired glucose tolerance (IGT). We conducted a doubleblind, placebo-controlled study with 3 groups; placebo, low dose group (red yeast rice 210.0mg/capsule, 2.52g/day) and high dose group (red yeast rice 420.0mg/capsule, 5.04g/day), which were randomly assigned to subjects with impaired fasting glucose or impaired glucose tolerance. We measured fasting serum concentrations of total-, LDL-, HDL-cholesterol, triglyceride, glucose, insulin, free fatty acid (FFA) and 2 h oral glucose tolerence test (OGTT) before and after the supplementation. Both low dose and high dose groups had significant decrease in LDL cholesterol and atherogenic index (AI) compared with placebo group (p<0.05). Additionally, total and HDL cholesterol improved significantly in high dose group compared with placebo group (p<0.05). Fasting serum glucose decreased in test groups and increased in placebo group after intervention. However, it was not significant differences. In subjects which fasting blood glucose is more than 110mg/dL, fasting glucose had a tendency to decrease in high dose group (p<0.1) and Hemoglobin A1c (HbA1c) had significant decrease in low dose group (p<0.05), while insulin and HOMA-IR had a tendency to increase in placebo group after intervention. Mean changes of glucose related parameters (fasting glucose, insulin, HOMA-IR) compared with placebo group did not show significant differences. In conclusion, subjects with impaired fasting glucose or impaired glucose tolerance were significantly improved in serum lipid profile by red yeast rice supplementation without serious side effects. These are more effective in the case of a high dose. The effects of red yeast rice supplementation on glucose control were insignificant.

Visualization Technology of GIS Associated with Seismic Fragility Analysis of Buried Pipelines in the Domestic Urban Area (국내 도심지 매설가스배관의 지진취약도 분석 연계 GIS 정보 가시화 기술)

  • Lee, Jinhyuk;Cha, Kyunghwa;Song, Sangguen;Kong, Jung Sik
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.2
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    • pp.177-185
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    • 2015
  • City-based Lifeline is expected to cause significant social and economic loss accompanied the secondary damage such as paralysis of urban functions and a large fire as well as the collapse caused by earthquake. Earthquake Disaster Response System of Korea is being operated with preparation, calculates the probability of failure of the facility through Seismic Fragility Model and evaluates the degree of earthquake disaster. In this paper, the time history analysis of buried gas pipeline in city-based lifeline was performed with consideration for ground characteristics and also seismic fragility model was developed by maximum likelihood estimation method. Analysis model was selected as the high-pressure pipe and the normal-pressure pipe buried in the city of Seoul, Korea's representative, modeling of soil was used for Winkler foundation model. Also, method to apply developed fragility model at GIS is presented.